OpenAI stopped releasing information about their models after gpt-3, which was 175b, but the leaks and rumours that gpt-4 is an 8x220 billion parameter model are most certainly correct. 4o is likely a distilled 220b model. Other commercial offerings are going to be in the same ballpark. Comparing these to llama 3 8b is like comparing a bicycle or a car to a train or cruise ship when you need to transport a few dozen passengers at best. There are local models in the 70-240b range that are more than capable of competing with commercial offerings if you're willing to look at anything that isn't bleeding edge state of the art.